This invention relates to athletic footwear, and particularly to the forefoot portion of athletic footwear. Many athletic movements in activities such as aerobic dance and basketball involve foot impacts which are initiated or concentrated on the forefoot. Even runners whose feet are of a high arch rigid structure will make initial impact with the surface on the fore part region of the foot.
Vertical ground reaction forces associated with such forefoot activities are considerably higher than those recorded for normal walking. Magnitudes of 4 to 5 times body weight have been reported for movements in aerobic dance and in basketball rebounding. A midfoot striking runner will exhibit a vertical ground reaction force spike of 2 to 3 times body weight, but because of the forefoot kinematics involved cannot easily attenuate shock through pronation.
Many overuse injuries such as stress fractures, tendonitis and muscle tears have been attributed to these high level magnitudes and velocities of ground reaction force loading.
The structure of copending application Ser. No. 339,198, filed Apr. 14, 1989, was developed for heel strike activities, but is not effective for forefoot and midfoot strike action.